Plastic tanks are widely used in hydraulic systems to contain hydraulic fluids. Because of the possibility of relatively simple configuration, low weight, and corrosion resistance, plastic tanks are extensively used, especially in hydraulic systems of machines such as excavators, wheel loaders, and the like.
Such tanks are usually produced by well-known or conventional rotomolding or blow molding processes. Polyethylene or polyamide plastics, for example, are used for larger containers, such as tanks for hydraulic fluids.
The advantages of corrosion resistance, low weight, and ease of molding are offset in the case of plastic tanks, however, by the disadvantage that production of fluid-conducting connections at openings in the plastic wall of the container or tank occasions certain difficulties. Because of the physical properties of the plastic material, the danger exists that deformations may occur in the area of the opening as a result of sealing forces and temperature effects. Such deformations can lead to leaking between plastic tanks and add-on elements, even if costly sealing elements are employed.